In the design and manufacturing process of the liquid crystal display panel, when designing the signal trace of the panel, besides some basic signal lines (such as a gate signal line and a data signal line) necessarily configured necessary for the product function thereof (normal display), the designer may further retain some other signal lines which detect whether the product performance is completed. Usually, before the liquid crystal display panel is bonded with the flexible printed circuit (FPC) board or driver IC, these signal lines may be connected to the cell test pad, it is convenient to the tester uses the oscilloscope to detect the electric signal state of the signal lines, so as to analyze the working state of the circuit inside the liquid crystal cell. During the latter production perion, these signal circuits are connected by the circuits, and a particular voltage level is inputted, such that some unnecessary circuits (not used when design testing and module producing) inside the cell of the liquid crystal panel are shorted or opened.
In order to achieve the unnecessary circuits to short or open, the trace of the circuit on the array substrate needing to be tested is usually connected to the cell test pad through the expert, which is used for the tester to detect. On the other side of the test pad, the trace is designed to connect to the bonding pin of the driver IC or the flexible printed circuit board. When bonding the driver IC or the flexible printed circuit board, a circuit trace is designed on the flexible printed circuit board, it is used to connect to the pad of the required voltage level and the pad of the cell test pad, such that this voltage level is transmitted to the cell of the liquid crystal panel again through the cell test pad, thereby shorting or opening some unnecessary circuits. The above scheme means that the potential of the driver IC or the flexible printed circuit board bonded on the pad is led back to the thin film transistor array substrate by using the circuit trace on the flexible printed circuit board served as a bridging. Although it is possible to achieve its necessary functions, the disadvantage thereof is that is needs more pads, it does not decrease the number of the pad when bonding the driver IC or the flexible printed circuit board, it does not reduce the area of the flexible printed circuit board or reduce the size of the driver IC, and it can bond the driver IC by necessarily using the flexible printed circuit board, such that this process does not obtain more benefits.